Radio frequency (RF) technology is becoming increasingly more common in a wide variety of uses. RF technology is relatively easy to utilize and RF sensing is well developed and recognized in many areas, such as inventory control, to prevent theft, proper routing of packages or the like, etc.
As used with identifying, routing, or inventorying envelopes, packages or other containers, RF technology often utilizes labels as either the product containing the RF technology, or in association therewith. For example as shown in U.S. Pat. No. 5,497,140 a label (such as a postage stamp or a mailing label) is provided having a radio frequency identification (RFID) device and system mounted between opposing faces of the major surfaces of the label. An RFID chip is electrically connected to an RF antenna that is contained with, or is part of, the label, thereby allowing the label to be simply applied to an envelope or package in order to provide proper tracking. Further, Motorola has introduced wireless smart label technology using "BiStatix.TM. Smart Labels" to efficiently track mail containers. A typical BiStatix.TM. label is approximately four inches by four inches, and contains both the antenna and the chip, and has a read or sensing distance of about one meter (that is the RF receiver sensor must be within one meter of the labeled package in order for proper sensing). While this technology is very useful, there are many situations in which it is desirable to allow sensing at greater distances and/or perhaps with better accuracy, and with less chance for interference, and to do so in a simple and cost effective manner. According to the present invention that is possible.
According to the most basic aspect of the present invention, a container wall/surface has a relatively large RF antenna disposed thereon, typically by printing a wall or surface of the container (which may be a package or an envelope, of the types commonly mailed or otherwise sent for delivery) printed with conventional conductive ink. Very large areas of the envelope, package, or other container may be printed with the conductive ink in a simple manner, and the printing may be done in an aesthetic manner with various designs, geometric elements, or the like, or it may be done with recognizable letters or characters so that to one viewing the container it isn't clear that the RF technology has even been utilized therewith. Then an element of the container, such as flap of an envelope, or a carton flap of a package, which has the RF technology (particularly an RFID chip) associated therewith may be used to bridge electrically non-conductive material between portions of the large antenna that has been printed with conductive ink on the substrate. While a wide variety of techniques may be utilized, typically the chip is provided on a label which has electrically conductive adhesive (typically pressure sensitive adhesive), and the label can be placed into contact with spaced portions of the antenna that has been printed on the container, electrically connecting portions of the conductive ink which are spaced from each other to the RFID chip. In this way the container may be produced--with the large antenna (e.g. for example between 25-200 square inches, such as a 12 inch.times.12 inch area)--while the RFID chip is added at some other location at some remote point in time, allowing for simple manufacture. Utilizing the invention it is possible to very accurately sense or read an RFID chip associated with the envelope, package, or like container at distances of at least about two meters, and typically at least about three meters, for example between about two-five meters. Thus the invention provides improved functionality without significant cost, and in an easy and effective manner, which greatly facilitates utilization of RF technology, and enhances functionality thereof.
According to one aspect of the present invention there is provided a container comprising: At least one container wall having a surface area. A first area of conductive ink at least in part disposed on the container wall and spaced from a second area of conductive ink, the first and second areas of conductive ink separated by substantially electrically non-conductive material, the first and second areas of conductive ink comprising at least part of an RF antenna. A label having a first face, and a second face. The second face having adhesive over at least a portion thereof, capable of attaching the label to the container wall. The label having an RFID chip mounted thereon. And, electrically conductive material associated with the label second face and positioned to connect the first and second areas of conductive ink to the RFID chip when the label second face is placed in a position engaging the first and second areas of conductive ink and bridges the area of substantially non-conductive material, so that the container is detectable by an RF receiver.
The second area of the conductive ink may be disposed at least in part on the container wall, but the first and second areas may each cover, or at least touch, the plurality of walls, and different walls. The adhesive and the electrically conductive material associated with the label for bridging the first and second areas may be essentially one in the same--namely a conventional electrically conductive adhesive, most preferably a conventional electrically conductive pressure sensitive adhesive. Typically the RFID chip is mounted on the label second face, however it may be mounted on the first face with connections between the chip and the electrically conductive adhesive, or other electrically conductive components, on the second face of the label, and a covering layer may be provided over the RFID chip is desired. For example see co-pending application Ser. No. 09/393,291, filed Sep. 10, 1999 . The label first face may include at least one of human and machine readable indicia thereon, such as address information, postage, bar codes, etc.
The first area, and also the second area if desired, may be in the form of at least one recognizable letter or character, and the first and second areas may cooperate together to spell out a word, make a complete design or character, or the like. The conductive ink in the first and second areas may be printed in any aesthetic manner desired, forming geometric designs that are pleasing to the eye, conveying information, or the like.
Typically, the container comprises a package or envelope of substantially electrically non-conductive material, such as paper, cardboard, paper board, or like cellulosic materials. Tyvek.RTM. sheet material. etc. For example, the container may comprise a substantially prismatic package (or envelope), primarily of cellulosic material, and in that case, the substantially electrically non-conductive material separating the first and second areas of conductive ink may comprise a part of the package (or envelope) substantially devoid of conductive ink.
The container wall may be inside the final passage or other container, outside or both. However, preferably the container wall or walls containing the electrically conductive ink first and second areas is at least primarily (if not exclusively) on the exterior of the package.
Typically, the antenna areas are dimensioned, and the packages (or envelope) constructed so that the package (or envelope) is detectable by an RF receiver and at a distance of at least about 2 meters, preferably at least about 3 meters (e.g., about 2-5 meters). This is typically accomplished by providing a much larger antenna area, provided by the first and second areas of conductive ink, than in the conventional labels, which in the case of the Motorola BiStatix system are typically only about 4".times.4" and detectable at a maximum distance of about a meter. According to the invention, for example, the first and second areas may collectively be more than 25 square inches, preferably more than 50 square inches, e.g., approximately 25-200 square inches. One particularly desirable size utilizable for many packages or large envelopes is about 12".times.12" (e.g., about 140-150 square inches) of conductive ink forming the first and second areas defining the antenna.
According to another aspect of the present invention, the package or envelope is provided comprising the following components: At least one wall having a surface area. A first area of conductive ink at least in part disposed on the wall and spaced from a second area of conductive ink, the first and second areas of conductive ink separated by a substantially electrically non-conductive material, portion of the package or envelope, the first and second areas of conductive ink comprising at least part of an RF antenna. An element having first and second faces, and having an RFID chip mounted therewith. The second face of the element having electrically conductive pressure sensitive adhesive over at least a portion thereof, capable of attaching the element to the wall. Electrically conductive material associated with the element second face and positioned to connect the first and second areas of conductive ink to the RFID chip when the element second face is placed in a position engaging the first and second areas of conductive ink and bridges the area of substantially non-conductive material, so that the package or envelope is detectable by an RF receiver.
The wall may comprise a face of an envelope or package which is engaged by the flap to seal the envelope or package, and the element may comprise an envelope or package flap. The first and second areas collectively may be approximately 25 square inches-200 square inches, so as to allow detection by an RF receiver from two meters or more away. At least the first area may be in the form of at least one recognizable letter or character, geometric design, or other aesthetic rendering.
According to another aspect of the invention, there is provided a container comprising at least one container wall having a surface area. A first area of conductive ink at least in part disposed on the container wall and spaced from a second area of conductive ink, the first and second areas of conductive ink separated by substantially electrically non-conductive material, the first and second areas of conductive ink comprising at least part of an RF antenna. A label having a first face, and a second face. The second face having adhesive over at least a portion thereof, capable of attaching the label to the container wall. The label having an RFID chip mounted thereon. And, electrically conductive material associated with the label second face and positioned to connect the first and second areas of conductive ink to the RFID chip when the label second face is placed in a position engaging the first and second areas of conductive ink and bridges the area of substantially non-conductive material, so that the container is detectable by an RF receiver.
According to another aspect of the invention, there is provided a method of constructing an RF detectable package or envelope having at least one wall, and of substantially electrically non-conductive material, using an element having an RFID chip mounted thereon and an electrically conductive bridging portion, comprising: a) Printing electrically conductive ink on the package or envelope. Including the at least one wall, to define first and second areas of electrically conductive ink, separated from each other by a portion of the package or envelope substantially devoid of electrically conductive ink. b) Bringing the element into bridging contact between the first and second areas of electrically conductive ink to connect the first and second areas of conductive ink to the RFID chip by the element bridging portion operatively engaging the first and second areas of conductive ink, so that the package or envelope is detectable by an RF receiver. And c) fastening the element in the bridging position.
In the practice of the method, when the element is a separate label having adhesive on the second face thereof, (b) is practiced by bringing a label into bridging position with the adhesive engaging the package or envelope, and (c) is practiced by activating the adhesive so that the adhesive holds the label in place. Typically, the label adhesive is pressure sensitive adhesive (although other types of adhesive may be used) in which case (c) is practiced by applying pressure to the label.
When the element is part of a package or envelope containing pressure sensitive adhesive, (b) and (c) are practiced by bringing the adhesive into contact with another part of the package or envelope, and pressing on it to hold it in place. For example, the element may be a flap of a package or envelope, in which case (b) and (c) are practiced by folding the flap into contact with another part of the package or envelope and pressing on it. Preferably, (a) through (c) are practiced so that the package or envelope may be detected by an RF detector at a distance of more than 2 meters, e.g., about 2 to 5 meters.
The practice of the method of the invention allows great flexibility in where and when various aspects are practiced, rather than requiring all be done at the same place. For example, according to the invention, (b) and (c) may be practiced in a different, remote location than (a), and at a remote time, for example, at least about 2 days later, and essentially anytime later since the conductive ink applied to the package or envelope will not significantly deteriorate over time. Also, (a) may be practiced so that the first and second areas collectively are at least 50 square inches.
It is the primary object of the present invention to provide an enhanced, RFID system and method, particularly in association with a container, such as an envelope or package. This and other objects of the invention will become clear from an inspection of the detailed description of the invention and from the appended claims.